An observation re: payment dates. I began receiving spousal SS on my wife's account, then switched to my own account at age 70. Her birthday is the 18th, hence 3rd Wednesday payment. When I was getting spousal SS, I also received it on the 3rd Wednesday, even though my birthday is the 21st (4th Wednesday). However, when I began drawing on my own account, the payments are still coming on the 3rd Wednesday. This may be an exception to the general rule.
Hi. I'm actually not sure if your case is an exception to Social Security's normal practice or not. Social Security doesn't put the systems manual section of their operations manual on the internet, so I can't check to see if Social Security ever moves payment dates to a later day of the month when a person changes from spousal benefits to their own benefits.
The general rule is that a person's payment date is determined by the birthdate of the worker on whose record the Social Security benefits are paid. So, it was certainly proper for your spousal benefits to have been paid on the 3rd Wednesday of the month based on your wife's birthday (https://faq.ssa.gov/en-us/Topic/article/KA-01957).
I do know that Social Security will sometimes changes a person's normal payment date to an earlier Wednesday when they change to drawing a different type of benefit, but I don't know for sure if changing benefit types ever causes a person's payment date to be moved to a later day of the month. In any case, it appears to have worked out well for you to start out drawing on your wife's account before switching to your own account.
Best, Jerry